PATIENT CHARACTERISTICS: Age: 18 and over Menopausal status: Not specified Performance status: ECOG 0-1 Life expectancy: At least 3 months Hematopoietic: Granulocyte count greater than 1,200/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin normal SGOT/SGPT less than 5 times upper limit of normal Albumin at least 3.0 g/dL No history of liver disease No positive hepatitis B or C antigen Renal: Creatinine no greater than 1.4 mg/dL Cardiovascular: No history of coronary artery disease No New York Association class II-IV heart disease No arrhythmia requiring treatment No contraindications to pressor therapy Pulmonary: FEV1 and FVC greater than 65% of predicted value Pulmonary function test required of patients with significant smoking history or possible pulmonary disease Other: No active peptic ulcer disease No known allergy to omeprazole No history of seizure disorders No other concurrent malignancy No concurrent medical or psychiatric condition that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception